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Abstract
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Background
One of the most significant costs associated with automobile travel in the US is the number of road accidents and fatalities that this type of transportation incurs. To control these costs, in 2015, the USDOT announced that "zero road deaths" is the official policy of the US federal government transportation safety. This policy envisions zero deaths as the ultimate road safety goal. To achieve this ambition, we need a consistent understanding of all potential determinants of road safety in the national level. Accordingly, this research provides a framework to investigate the impact of a wide range of variables on traffic fatality rates (defined as deaths per 100,000 people). We particularly examine the effect of auto-dependency indicators, public health factors, and active transportation modes on the road safety outcomes.
Methods
For this purpose, a previously developed conceptual framework has been used which classified road safety contributing factors into seven separate sets: exposure, travel behavior, socio-economics, infrastructure and urban form, safety policies, and mitigating factors such as health care. This framework is tested using series of panel data models. These models investigate both spatial and temporal variations in safety patterns for the fifty states, along with DC, using annual data from 1997 to 2014. A complimentary analysis is conducted to assess the impact of factors which just available for few years of analysis like walking and biking variables.
Results
The results of our panel models illustrate that two variables Vehicle Miles Traveled and Vehicles per Capita , representing the level of auto-dependency, have the strongest impact on traffic fatalities. The elasticity analysis reveals that a 10% increase in VMT per vehicle is associated with 8.6% increase in road fatalities. Likewise, a 10% increase in vehicle ownership rate results in a 8.0% increase in road fatalities. This is closely followed by Infant Mortality Rates, the proxy that we used to represent the public health care. The results of complimentary analysis show that states with higher urban density, more walking, and more cycling are associated with lower traffic fatality rates.
Conclusions
Our findings suggest that if additional progress is to be made in reducing traffic fatalities, emphasis needs to move beyond simply focusing on policies such as seat belt laws. This research provides an order of factors influencing road fatalities, this order can help American policy makers to provide a more efficient road map for progress towards zero road death target. |